I let someone else use my playbook for a little while and it started acting weird. It wouldn't even install apps anymore.

I decided to do a security wipe. After that, it needed to download over 300 mb of extra updates before it would let me use the tab.

That's where I ran into problems. It would download the updates, and then tell me it couldn't install them. I tried to update 7 more times to no avail.

I finally had a weird idea, which I was sure wouldn't work. I decided I would try to update one more time, but swirl my finger around on the screen constantly to keep the screen from turning off all the way through download and installation.

Sure enough, it actually worked! So the automatic screen turn off was corrupting the updates.